Its a little mixture of just the basic advice. Breath slow, centre your breathing, speak slow, stretch your words if need be and try and remain calm. To really be successful with it, you need to be calm and that's hard enough to do. I was calm until my voice cracked on a call and infront of colleagues, too embarrassing. Speaking slow helps to stretch your words if necessary and I found it helpful. It's honestly taken too long to get to it but at the same time, I've only been trying this exact method for a day and a half